Method of making tire-casing carcasses.



W. C. STEVENS MEIHOD OF MAKING TIRE CASING CARCASSES APPLICATION FILED sEPr. ZIP-Hi3- 1,258,056. Patented Mar. 5, 191&

-2 SHEETSSHEET I.

W. C. STEVENS.

mmoo 6F MAKING me cnsmc GARCASSES.

APPLICATlON FlLED SEPT-27' I913.

1 ,258,056 Patented Mar. 5, 1918.

2 SHEETS-SHEU' 2.

W566, .JfwenZZfi 1 32% UNITED STATES PATENT OFFICE.

WILLIAM G. STEVENS, 0F AKRON, OHIO, ASSIGLlOR TO THE FIRESTONE TIRE 8c RUBBER COMPANY, OF AKRON, OHIO, A CORPORATION OF OHIO.

METHOD OF MAKING TIRE-CASING CARGASSES.

Specification of Letters Yatent.

Patented Mar. 5,1918.

Application filed September 27, 1913. Serial No. 792,076.

Akron, in the county of Summit and State of Ohio, have invented certain new and useful Improvements in Methods of Making Tire-Casing Carcasses. of which the Follow infiiis a specification.

invention relates to the art of making or s aping tire-carcasses, a tire-carcass as understood in this art beingthe shaped mass of rubber and fabric, which, after the addition of the tread and other parts of the tireof the whole in a automobiles and similar vehicles.

Prior to my nvention, such tirecarcasses have been ordinarily made by shaping suecessive layers or lies of materiah rubber frictioned fabric, or instance, on a tire-core or form as follows: The operator applies :1 ply of the fabric to the periphery of the "annular core, cementing it in place more or less to cause its adhesiom and stretching it during such application, as itjs always out He is rarely able to judge sojhe is likely to stretch it much. lll

i which'case the ply becomes overstretched and weakened and he is compelled to out off a portion; or, he is likely tostretch it too little, in which case he has to remove a part of the ply from the form, stretch the detached section still further, and replace it in position on the core. The efi'ect of this latter proceeding is that the strip of the fabric is stretched irregularly, some parts more than others, and successive plies are not always stretched to the same degree. In carrying out this hand process, the workman grasps the side-portions of the ply and stretches it by pulling on such sections. which necessarily unduly elongates such sideportions, thereby rendering more difiicult the subsequentabsorption of the fullness in the sides'ofthe carcass.

It has been heretofore proposed to make suchtire-cnrcasses by machines, but in all of these devices which I am acquainted with. in order to reduce the amount of fullness of the fabric-stock which must be absorbed and cared for in the sides of the carcass, undue stretching of the tread-portion of the ply is employed, with the obvious weakenmg of the completed structure and an improper distortion or distribution of the threads of the fabric.

In these machine-made carcasses it has also been practically impossible to stretch the various plies of fabric to the same degree uniformly throughout their length. but. in carrying out my improved process I take care that the plies 'are always stretched lengthwise to the same degree and uniformly throughout their entire lenflgth. I may employ any desired means for e ecting the results indicated. Owing to the fact that the series of plies ordinarily vary in width, the inner ones being narrower and theouter ones wider, it is necessary to modify the pull or force exerted on the various plies "because of this difference in width, in order to secure the same percentage of elongation of each, that is, the same percentage of increase overthe original length. One such means for stretching the fabric in the manner indicated "is shown in my co-pending application for the apparatus, Serial No. 760,615, filed April 4, 1913.

I also shape to the side faces of thecore the edge-portions of the fabric in such a manner as to aroid they fortnation of'wrinkles during the shaping-operation. This result I effect by pressure applied in acertain direction and manner which I shall proceed to detail. The pressure which is of a rubbing kind is applied along a. line or plane of short but appreciable length, the direction of which is oblique to the radius of the core or to the direction of progress of the pressure, as presently to be described. This line of pressure is made to progress toward the center or axis of the coreover a series of successive zones of the fabric of narrow dimensions, such series taking usually the form of a fine spiral. The ramakes the adjustment ofthe threads gradual and accomplished with comparative facility. The influence or effect of the fulling or condensing extends beyond the immediate path of pressure somewhat into the unattached portion of the fabric, which, in this way is preliminarily or initially prepared for the pressing-agent. Thus, the threads of the fabric have been disturbed a littie and are more readily moved or drawn into the compacted parallelisms heretofore referred to.

Much depends upon the kind of pressure applied and upon the manner of application. I find that the pressure should be of a smoothing or rubbing character, the rubbing-effect being carried generally but not necessarily directly centerward. The effect which I find to be best is that produced by the edge of an individual roller, such as the fabric-applying or smoothing roller of my patent application above referred to, arranged in a plane somewhat oblique to the direction of rotation of the core. The path of the roller edge on the face of the fabric is thus several times the width of the edge and as the core turns or revolves the material is pressed, compacted, smoothed, and fulled into position in a narrow path, and this is repeated as long as the rotation of the core and the radial movement of the pressing agent brings new portions of the material under the influence of the pressing and smoothing-roller.

Briefly stated, the principal object of my improved process or method is to make a tire-carcass free from all traces of wrinkles, folds, or similar defects in the frictionedfabric. That is to say, the formation of such defects is prevented so that they do not subsequently require elimination.

In order that those skilled in this art may have a full and complete understanding of this process or method, I haye descr bed the same in the accompanying drawings forming a part of this specification.

In these drawings:

Fi ure 1 illustrates the stretching of a ply of fa ric on the form or core;

Fig. 2 illustrates the'smoothing of the side-portions of the fabric and the application of the same to the form or .core;

Fig. 3 also illustrates the manner of applying the edge-portions of the fabrih to the form- Fig 4 shows the manner of applying one of the plies or layers of fabric overthe bead, and. t

Fig. 5 is a cross-sectional view illustrating the same portion of the process.

In the particular means illustrated in these drawings for carrying out my novel process. there is provided a suitably driven revoluble form or core 10. a retarding roller 11 pressed against and adapted to travel on the periphery of such form or core or ply already applied thereto, such retardingroller 11 being mounted ,on a shaft 12 connected to another shaft 13 by intermeshing gearsl l and 15. shaft 13 carrying a Stretching-roller 16. The rubber frictioned fabric having been previously wound up with an interposed cotton cloth liner on the supplydrum 17 has it forward end passed around an idler 18 and over the stretching-roller 16 to the core to which its advance end is cemented. Then the form or core 10 is revolved relatively slowl in the direction indicated by "the arrow illustrated in Fig. 1, and the fabric )ly as it is applied in this manner to the vorm is stretched uniformly throughout its entire length, the'stretchingroller 16' being retarded in its rotation oning to the frictional engagement of the retarding-roller 11 with the form and the gearin connection between the two shafts 12 an 13, whereby a predeterminedand definite stretch is given tothe fabric as it is applied to the form. As the fabric unwinds from the stock-roller 17, the cotton cloth liner is automatically wound up onthe drum 19. The rear end of the first ply of fabric is then disconnected from the advance end of the second ply to which it had been temporarily secured, and the end of the second ply is, for the time being, thrown back out of cooperative relation with the core and stretching-drum 16.

Then the form with the first ply stretched thereon is rotated at a higher speed, it be ing understood that the central portion of such ply, by the stretching operation was caused to adhere smoothly and evenl to the outer portion or face of t e form, t 3: sidesections of the ply, however, not havin yet peen smgothed iiilto lafie on thd ideseithe orm. urin t is ig ersp e .o tatiorE the side-porti ns 20 and 21 of the fa ic ai'e thrown out more or less by centrifugal force and during such rotation, a pair" of thin disks or rollers 22, 22, yieldingly pressed toward one another are caused to enga e the sides of the fabri and travel slow y inwardly toward the axis of the form, therehv applying the side-portions of the ply to the form free from wrinkles, folds, or other blemishes, the fullness bein gradually and completely absorbed in the abric, due to the compacting and condensing effect of these disks or. rollers on the fabric. This is brought about due to the pecuriar disposition of the rollers. Tifey are tilted or canted slightly with respect to the direction of rotation of the form so that they work diagonally crosswise of each of the successive zones of the fabric as the rollers travel inwardly centerward of the form. Due to such diagonal or canted arrangement of the rollers they stretch each zone of fabric that they act on transversely, which facilitates 0 a smooth a plication of the fabric transversely of tie form or core, but th 1s transverse stretching of the zone of fabric 1s also instrumental in circumferentially shortening such zone, thereby rendering its apphcation to the form without wrinkles or defects easier. This action of the roller on the zone of fabric is not confined solely to the particular zone under the roller, but extends more or less outwardly into the unattached portions of the fabric. preliminarily shortening such unattached sections of the ply and thereby initially preparing them for application to those portions of the form of lesser circumference.

If the rollers merely rolled on the fabric and traveled inwardly toward the center without being inclined to the direction of rotation of the form. that is. dis posed diagonally of the zone of fabric on which they are acting. then this peculiar shortening-effect whereby the absorption of the fullness is largely secured would not he obtained. Owing to the fact that the rollers 22 yieldingly press toward the form. they readily follow the contour of the latter and apply the fabric rapidly. ellicicntly. and

. without defect After the first ply has been stretched on the form and its sides rolled down into place, succeeding plies are treated in the same manner, and at the proper time the beads 23, 23. are cemented into place on the opposite sides of the mlrcass under construction. In rolling down the succeeding plies of fabric over the beads. particularly those portions of the ply caused to adhere to the surface of the beads between their toes and heels, the angular relation of the rollers may be shifted somewhat as illustrated in Figs. 4 and 5 to more effectively travel over such abrupt surfaces. but their diagonal relation with respect to the direction of ro tation of the form is maintained in all instances to secure the application of the fabric without wrinkles. In order to obtain this. it will be understood that the rollers are so disposed as to apply pressure against the face of the carcass-strip along lines oblioue to the direction of progress. with the outer ends of such lines leading; otherwise the rollers would not stretch the fabric transversely of the form as is desirable. It should be observed that in carrying out this method the fullness in the fabric is effectively cared for without pushing it ahead of the roller circumferentially of the form. the roller not only literally stret-chiiig the cloth but at the same time inwardly wiping or ironing out the wrinkles and simultanetmsly applying the fabric to the core or underlying ply so that the fullness once absorbed in the applied ply cannot reappear.

From the above it should be clea r that in accordance with my novel method each ply is individually stretched on the form and then smoothed down On the sides of the same before the next ply is stretched and a plied. It should also be obvious that t e fabric plies arestretched only the required amount to maintain the completed tire-shoe or casing in normal shape and with proper strength, this being possible owingto the peculiarglction of the smoothing-rollers in stretching the fabric transversely and at the same time shortening it circumferentially. The result is that no wrinkles or similar blemishes are permitted to form in thefabric during the application of the side sections of the ly to the core or carcass, and. consequent y there is no necessity for subsequcntly attempting to overcome the elfects of such wrinkles. folds. or similar defects. Stated differently. I avoid the efl'ects of and the presence of such defects in the completed tire-shoe or casing by preventing their occurrence as the fabric is smoothed down on the form rather than place reliance upon an attempte-l elimination of such faults after they have occurred.

In carrying out my method I am able to apply the side-portions of the plies of fabric in place on the core or carcass with facility and dcspatch over the entire surface from the brow or tread-portion of the core around over the head to the inner edge or toe of the latter. and in addition, each ply before such smoothing is uniformlystretched as described. throughout its entire length so that in the complete tire-structure these \a' rious superposed plies give mutual support to one another by reason of their cumulative and uniform capacity for resistance against internal pressure.

By this process the detrimental overstretching of the fabric hereinabove referred to, with its resulting weakening of the finished tire-casing or shoe is entirely overcome, since, as exp ained, it; is not necessary to unduly stretch the fabric if the fullness is absorbed. in the sides of the tire by this process.

I claim:

1. The method of making tire-carcasses, which consists in stretching a ply of fabric uniformly throughout its length, conforming the middle section of such ply to the shape desired, then conforming the sides of the ply to the shape required, then stretching a second ply of greater Width to the same degree in the same manner over the first ply. and then conforming the sides of such second ply to the shape desired over the first ply. substantially as described.

2. The method of making tire-carcasses, which consists in stretching a ply of fabric uniftnmly throughout its length and simultaneously conforming the middle section of such ply to the shape desired, then conforming the sides of the ply to the required shape,

then stretching a second ply of greater width to the same degree in the same manner over the first ply, and then conforming the sides of, such second ply to the shape desired over the first ply, substantially as described.

3. The method of constructing tire-carcasses, which consists in stretching in succession plies of fabric of different widths each uniformly lengthwise to the same degree, conforming the middle part of each ply in succession to the shape required for it and at the same time bringim such middle part of each ply, (except the ffrsh) into intimate adherent relation with the one beneath it, and also in the same succession shaping and smoothing the sides of each ply to the form desired by continuous pressure directed against its face and proceeding in- Wardly toward the inner edges of the tire, substantially as described.

4. The method of constructing tire-carcasses, which consists in stretching in succession plies of adhesive fabric of different Widths, each uniformly lengthwise to the same degree, and simultaneously conforming the middle part of each ply, (except the first,) into intimate adherent relation with the one beneath it by the stretching operation, and also in the same succession shaping and smoothing the sides of each ply to the form desired by continuous pressure directed against its face and proceeding inwardly toward the inner edges of thetire, substantially as described.

5. In the art of shaping tire-carcasses, the step which consists in bringing the sideortion of a strip of. fabric into conformity with the shape desired by pressure applied progressively against the face of the carcass strip along a single line oblique to the direction of the progress, the outer end of said line leading, substantially as described.

6. The art of shaping or smoothing down the edge portion of a ply of tire fabric to conform it to the shape desired which consists in applying to said portion pressure progressively in a single line oblique to the direction of progress, and causing successive portions of the ply to be subjected to the effect of said line of pressure while said line is caused to progress toward the center of the tire, substantially as described.

7. The method of shaping tire-carcasses, which consists in stretching uniformly in the direction of its length a ply of fabric, conforming said ply to the shape of the periphery of a tire carcass, then bringing the edge portions of said fabric to conformity with the side faces of the tire carcass and gradually smoothing the side-portions into position by progressive pressures applied to the faces of the tire carcass and in lines oblique to the direction of progress, said direction of progress being in the form of a spiral with a slowly decreasmg radius and repeating the steps indicated with additional plies until a carcass of required thick ness is formed, substantially as described,

8 The method of shaping tire carcasses, which consists in stretching uniformly in the direction of its length a ply of fabric, simultaneously conforming said ply to the shape of the periphery of a tire-carcass, then bringing the edge iortions of said fabric to conformity with the side faces of the tire r5 carcass and gradually smoothing thcside portions into position by progressive pressures applied to the faces of the tire carcass and in lines oblique to the direction of prog rcss, said direction of progress being in the form of a spiral with a slowly decreasing radius and repeating the steps indicated with additional plies until a carcass of required thickness is forn'led, substantially as described 9. In the art of shaping tire carcasses, the step which consists in bringing the side por tion of a strip of fabric into conformity with the shape desired by a progressive rub hing pressure applied against the face of the strip along a line oblique to the direction of progress, the outer end of said line of pressure leading, and the rubbing effect being applied from the outer end of said line in the direction of said line and at the same time inwardly in a spiral toward the middle of the carcass, substantially as de scribed.

10. The method of shaping the plies of fabric of tire-carcasses, comprising stretchlug lengthwise the middle part of a fabric ply, conforming such middle part to the shape required, and shaping the side-po tions of such ply to the desired form by applying traveling pressures progressing in a spiral from the conformed middle part of the ply forward from the edges in such manner that the succession of zones of fahric acted upon by the pressure are stretched in succession transversely and thereby coni. tracted circumferentially, and simultaneously compacting the fabric threads of such zones lengthwise of the latter, substantially as described 11. In the art of making tire-carcasses, the process of bringing the fabric layers to the proper shape, consisting in simultaneously stretching the fabric. layers inwardly toward the center of the tire, and applying them in position; the oint at which He stretching and application occu progressing spirally inward.

12. In the art of making tire-carcasses, the process of bringing the fabric layers to the proper shape, consisting in applying the center of a fabric layer about the crown of a form, the skirts being free, and then stretching the skirts of the fabric inwardly to the center of the form, and applying them to the form in their stretched cond1- 130 tion, the stretching and a plicat ion being performed in a spiral line about the sides 0 the form.

13. In the art of making tire-carcasses, the process of bringing the fabric to the proper shape, consisting in applying the center of a fabric layer about the crown of a form, the skirts being free, and then simultaneously stretching the skirts of the fabric inwardly to the center of the form and applying them to the form in their stretched condition, the application bein performed in a spiral line on the sides 0 the form.

14. In the'art of making tire-carcasses, the process of bringing the fabric layer to the proper shape, consisting in applyin the center of a layer about the crown of a cm, the skirts bein free, and stretching the skirts of the fabric inwardly to the center of the form; the point at which the stretching action takes lace being at the base of the skirt of the abric and advancing spirally inward toward the center of the form,

and applyin them to the form in their stretched con ition.

15. In the art of making tire-carcasses, the process of bringing the fabric layer to the proper shape ;consisting in stretching longitudinally and applying the center 0 a fabric layer about the crown of a form, the skirts of the fabric being free and unstretched, and then stretchin the skirts of the fabric transversely inwar 1y to the center of the form; the point at which the stretching takes place bein at the base of the skirts of the fabric an advancing spirally inward toward the center of the form, and applying them to the form in their stretched condition.

In witness whereof I have hereunto signed my name in the presence of two subscribed Witnesses.

WILLIAM G. STEVENS. Witnesses R. E. Guns, S. G. Casxmnm 

